Mechanical spring finger data storage system



Sept. 13, 1966 J. W. DAVIS 3,273,132

MECHANICAL SPRING FINGER DATA STORAGE SYSTEM Original Filed Aug. 21,1961 l6 -1| I2 \\3 :4 l5 6 I 25 26 30 2s 29 24 23 1 r I 1 "1 T M II :j\'$5 O O O O A; O O I:

O O O O O O O O I0 I! I2 13 l4 l5 l6 17 FIG. 2

INVENTOR. JOSEPH W. DAVIS BY #ZW flaw a ATTORNEY United States Patent3,273,132 MECHANICAL SPRING FINGER DATA STORAGE SYSTEM Joseph W. Davis,Chester Heights, Pa., assignor to General Atronics Corporation,Wyndmoor, Pa., a corporation of Pennsylvania Continuation of applicationSer. No. 132,880, Aug. 21, 1961. This application Dec. 9, 1964, Ser. No.418,947 2 Claims. (Cl. 340173) This invention relates to improvements indata storage systems of the type in which the stored data arerepresented by the position of spring fingers on one side or the otherof a barrier along which these spring fingers travel, the instantapplication being a continuation of application Ser. No. 132,880, filedAugust 21, 1961, now abandoned.

In such a system the above-mentioned barrier extends along a portion ofan endless path traveled by the spring fingers. This barrier ispositioned relative to said path so that, when the spring fingers areundeflected, they tend to travel along one side of the barrier. At theleading edge of the barrier there is stationed an electro-magnet whichis energizable to deflect selected ones of these spring fingers so thatthey will pass this leading edge on the side opposite to that on whichthey would normally pass it. Thereafter the barrier prevents thesedeflected spring fingers from returning to their undeflected positionsand constrains them to travel along the side of the barrier opposite tothat which they would follow in their undeflected condition. The patternof deflected and undeflected fingers thus produced represents the databeing stored. By disposing, at one or more points along the barrier,apparatus capable of sensing the passage of spring fingers along oneside or the other of this barrier, the stored data may be recoveredafter a storage interval dependent upon the speed of movement of thefingers along the barrier and the distance between its leading edge andthe sensing apparatus. Since deflection of the spring fingers, asdescribed above, places these fingers under ten sion, the deflectedfingers tend to return to their undeflected positions at the end oftheir travel along the barrier. This in effect erases the data stored bymeans of the deflected spring fingers and puts them in a condition inwhich new data can be stored by means of them as they pass the leadingedge of the barrier again in their next circuit around the endless pathin which they travel.

A storage system of this type has many uses. For example, it may be usedas a proportional memory for a material transporting conveyor. In thisapplication the spring fingers are caused to travel along the barrier insynchronism with the travel of the conveyor from its loading station toone or more discharge stations. Different destination codes may beimpressed on the one finger or group of fingers representing a givenconveyor section by positioning these fingers to one side or the otherof the barrier in difierent patterns. Apparatus sensitive to thesedifferent patterns is then disposed along the barrier at dilferentpositions corresponding, respectively, to the various discharge stationsof the conveyor and sensing by such apparatus of the particular patternto which it is sensitive, is utilized to cause discharge of the conveyorsection represented by the fingers disposed in this pattern.

In the type of data storage system under consideration it is necessarythat the undeflected fingers travel in very close proximity to, and infact preferably in contact with the barrier. This makes it possible todeflect the spring fingers to the opposite side of the barrier with aminimum of physical displacement, thus reducing the size and powerrequirements of the deflecting means and also the danger that the springfingers will be deflected beyond their elastic limits. However, thisclose spacing creates the following problem. In the course of operationof the system it is possible for the undeflected spring fingers toacquire slight unintended deflections from their desired undeflectedpositions. This may result from repeated intentional deflections or froma variety of other causes. Because of the close spacings discussedabove, spring fingers which have such slight unintended deflections maybecome caught on the leading edge of the barrier and may be misdirectedto the wrong side of the barrier or even become arrested by the barrier,causing the whole system to jam or the fingers to break. These mishapscannot be prevented by purely mechanical channeling means because suchchanneling means must necessarily stop short of the leading edge of thebarrier in order to provide an unconfined space in which the springfingers can be intentionally deflected from one side of the barrier tothe other.

Accordingly, it is the object of the invention to overcome the defectsoutlined above and to provide a data storage system of the type underdiscussion in which there is no substantial possibility of malfunctiondue to misalignment of the spring fingers approaching the leading edgeof the barrier.

This object is achieved by providing, in addition to the electro-magnetwhich is energizable to deflect selected ones of the spring fingers fromone side of the barrier to the other, an auxiliary magnet which producesa force opposing the deflection produced by the electro-magnet. Theauxiliary magnet is so arranged that it is unable to overcome thedeflecting force produced by the electromagnet when the latter isenergized, but is able to bring unintentially deflected spring fingersback into their desired undeflected positions when the electro-magnet isnot energized.

Further details are provided below with reference to the accompanyingdrawings in which FIGURE 1 shows that portion of the type of datastorage system under discussion which embodies the invention, and

FIGURE 2 is a top view of the apparatus shown in FIGURE 1.

Referring now to these figures, both illustrate that portion of a datastorage system of the type under discussion in which the transfer of thespring fingers from one side to another of the barrier is accomplished.Eight spring fingers 10 through 17 are shown, but it will be understoodthat additional spring fingers may be present both to the right and theleft of those illustrated as indicated diagrammatically by the pairs ofbroken lines 19 and 20 extending to the right and left of the springfingers in FIGURE 1. As shown in FIGURE 2, each spring finger is rivetedat one end to a link in a chain 21. This chain may be driven in anyconventional manner to cause the spring fingers to move from left toright, i.e. in the direction indicated by arrow 22 in the drawings.Chain 21 preferably forms an endless loop so that the spring fingersrecirculate repeatedly through the region illustrated in the drawings.

A section of the barrier forming part of the storage system is shown at23 in FIGURES 1 and 2. This barrier has a leading edge 24 which ispreferably wedgeshaped in the horizontal plane, as shown in FIGURE 2.

When the spring fingers are undeflected, their free ends travel along apath immediately adjacent the lower edge of barrier 23. Fingers 13 and16 are shown in that position in FIGURES 1 and 2. A guide strip 25,although not essential, is preferably provided below barrier 23, spacedfrom its lower edge by about the thickness of the spring fingers, forthe purpose of keeping to a minimum unintentional deviations of thespring fingers from their desired path along the lower edge of barrier23. Also preferably included is a pair of converging rails 26 and 27which end some distance to the left of the leading edge 24 of barrier 23and which, at their closest approach to said barrier, are aligned withits leading edge and with the adjacent end of guide strip 25,respectively. Spring fingers approaching the barrier 23 are constrainedto pass between these converging rails which tend to reduce unintendeddisplacements of these fingers from their desired approach path to thebarrier. Above the gap between rail 26 and the leading edge 24 ofbarrier 23 is an electromagnet 28 which is energizable simultaneouslywith the passage of selected spring fingers beneath it and responds tosuch energization to attract these spring fingers to itself, therebylifting them above barrier 23. This energization continues until theaffected finger has become engaged by the upper edge of barrier 23 whichthereafter prevents it from returning to its undefiected position in itsfurther travel along the barrier. Fingers 14 and 17 are shown in thisdeflected position in FIGURES 1 and 2. Electromagnet 28 may be energizedin any one of various conventional ways which form no part of theinvention and which are therefore not discussed further.

Any sensing apparatus which may be disposed along barrier 23 fordetecting the passage of spring fingers above and below this barrieralso forms no part of the present invention. In view of this, and inview of the fact that various forms of such sensing apparatus are known,this apparatus is also not discussed further herein.

In accordance with the present invention there is provided, in additionto electro-magnet 28, an auxiliary magnet 29, positioned below the planedefined by the lower edge of barrier 23 and in such relation to thepaths of the spring fingers that it begins to act on each one of themonly after this finger has entered the region in which it is subject tothe influence of electro-magnet 28, provided the latter is energized.The top surface of auxiliary magnet 29 is level with the top surface ofguide strip 25 which defines the lower limit of the path intended to befollowed by the undeflected spring fingers in relation to barrier 23.The strength of the auxiliary magnet, which may be either a permanentmagnet, or an electro-magnet energized continuously during operation ofthe storage system, is proportioned relative to that of electr c-magnet28 in such a way that it is unable to overcome the attraction exerted onthe spring fingers by the energized electromagnet 28. Consequently thepresence of the auxiliary magnet does not interfere With the ability ofelectro-magnet 28 to displace selected spring fingers to the top of thebarrier. However, if the electro-magnet 28 is not energized, thenauxiliary magnet 29 will be effective to keep the spring fingersapproaching barrier 23 below the lower edge of the barrier duringpassage of its leading edge 24, even though these finges may previouslyhave been unintentionally displaced so that, in the absence of themagnet 29, they would approach the barrier with a suflicient upwarddeflection to become caught on its leading edge.

In the preferred embodiment illustrated in FIGURES 1 and 2 there is alsoprovided a second auxiliary magnet 30, which may be similar to auxiliarymagnet 29 in its magnetic characteristic and which is disposed in thepath of the spring fingers ahead of the region in which they aresusceptible of being affected by the electro magnet 28. The top surfaceof this second auxiliary magnet 30 is preferably aligned with the topsurfaces of rail 27 and auxiliary magnet 29. Magnet 30 attracts to itstop surface spring fingers passing above it before they enter the regionin which electro-magnet 28 is able to affect them, thereby contributing,whenever electro-magnet 28 is unenergized, to the smooth transition ofthe spring fingers to the top surface of auxiliary magnet 29.

Various modifications of the apparatus described above will readilyoccur to those skilled in the art Without departing from the inventiveconcept. For example, a second electro-magnet 31, shown in FIGURE 1, maybe positioned in the gap between auxiliary magnets 29 and 30. Thissecond electro-magnet is energized whenever electromagnet 28 is notenergized and vice-versa. Thus, whenever electro-magnet 28 isunenergized, electro-magnet 31 provides for a smooth transition of thefingers from permanent magnet '29 to permanent magnet 30 therebyfacilitating still more the proper positioning of the undeflected springfingers below the lower edge of barrier 23.

I claim:

1. In a data storage system including a barrier, a plurality ofdeflectable spring fingers moving in their undeflected positions alongsaid barrier adjacent one side thereof, and electro-magnetic meansenergizable to deflect selected ones of said spring fingers at thebeginning of their movement along said barrier so as to cause them tomove adjacent the opposite side of said barrier, the improvementcomprising auxiliary magnetic means opposing said deflection produced bysaid electro-magnetic means, said auxiliary magnetic means havinginsuflicient strength to counteract the deflection produced by saidelectromagnetic means and comprising a first magnet positioned so thatany one of said moving spring fingers becomes subject to the substantialinfluence of said magnet after it has become subject to the influence ofsaid electro-magnet, and a second magnet so positioned that any one ofsaid moving spring fingers traverses the region in which it is subjectto the influence of said second magnet before becoming subject to thesubstantial influence of said electro-magnet.

2. In a data storage system including a barrier, a plurality ofdeflectable spring fingers movable in their undeflected positions alongsaid barrier adjacent one side thereof, and electro-magnetic meansenergizable to deflect selected ones of said spring fingers at thebeginning of their movement along said barrier so as to cause them tomove adjacent the opposite side of said barrier, the improvementcomprising first and second auxiliary magnetic means, each opposing saiddeflection produced by said electro-magnet-ic means, said firstauxiliary means comprising a magnet having insufficient strength tocounteract the deflection produced by said electro-magnetic means andpositioned so that any one of said moving spring fingers becomes subjectto the influence of said magnet after it has become subject to theinfluence of said electro-magnet and a second magnet so positioned thatany one of said moving spring fingers traverses the region in 'which itis subject to the influence of said second magnet before becomingsubject to the influence of said energized electro-magnet, and saidsecond auxiliary means comprising a second electromagnet disposedbetween said first and second magnets, said second electro-magnet beingenergizable alternately with said first mentioned electro-magnet.

References Cited by the Examiner UNITED STATES PATENTS 420,622 2/ 1890Dickerson 317-188 2,431,125 11/1947 Klaus 324-103 2,604,524 7/1952McCaine 317-188 2,817,796 12/1956 De Fligue 317-172 2,827,529 3/1958 DeFligue 200-93 2,861,145 11/1958 Gardiner 317-188 BERNARD KONICK, PrimaryExaminer.

IRVING L. SRAGOW, Examiner.

T. W. FEARS, Assistant Examiner,

1. IN A DATA STORAGE SYSTEM INCLUDING A BARRIER, A PLURALITY OFDEFLECTABLE SPRING FINGERS MOVING IN THEIR UNDEFLECTED POSITIONS ALONGSAID BARRIER ADJACENT ONE SIDE THEREOF, AND ELECTRO-MAGNETIC MEANSENERGIZABLE TO DEFLECT SELECTED ONES OF SAID SPRING FINGERS AT THEBEGINNING OF THEIR MOVEMENT ALONG SAID BARRIER SO AS TO CAUSE THEM TOMOVE ADJACENT THE OPPOSITE SIDE OF SAID BARRIER, THE IMPROVEMENTCOMPRISING AUXILIARY MAGNETIC MEANS OPPOSING SAID DEFLECTION PRODUCED BYSAID ELECTRO-MAGNETIC MEANS, SAID AUXILIARY MAGNETIC MEANS HAVING INSUFFICIENT STRENGTH TO COUNTERACT THE DEFLECTION PRODUCED BY SAIDELECTRO-MAGNETIC MEANS AND COMPRISING A FIRST MAGNET POSITIONED SO THATANY ONE OF SAID MOVING SPRING FINGERS BECOMES SUBJECT TO THE SUBSTANTIALINFLUENCE OF SAID ELECTRO-MAGNET, AND COME SUBJECT TO THE INFLUENCE OFSAID ELECTRO-MAGNET, A SECOND MAGNET SO POSITIONED THAT ANY ONE OF SAIDMOVING SPRING FINGERS TRAVERSES THE REGION IN WHICH IT IS SUBJECT TO THEINFLUENCE OF SAID SECOND MAGNET BEFORE BECOMING SUBJECT TO THESUBSTANTIAL INFLUENCE OF SAID ELECTRO-MAGNET.